Barry Lane of England and Boonchu Ruangkit of Thailand are two shots behind the leaders after opening-round, 5-under 67s. There are six players tied for fifth place one stroke further back.
The 65s of Delamontagne and Plaphol established a new course record at the re- designed Shenzhen Golf Club.
Delamontagne, who finished a career-best 68th on the Order of Merit during the 2005 season, mixed six birdies and an eagle with just one bogey in his round.
Plaphol, who was part of a good showing by Asian Tour players in this co- sanctioned event, carded five birdies and two eagles to go along with two bogeys for his 65.
Delamontagne started on the back nine and made the turn at 5 under after three birdies and an eagle at the 18th. He moved to minus-6 with another birdie at the first before dropping his only stroke with a three-putt bogey at the second.
The 26-year-old got that stroke back and another when he followed with consecutive birdies at Nos. 3 and 4. He then finished off his round with five straight pars.
Delamontagne is looking to carry over some of the success he had during a 2005 season that included a tie for fourth-place at the Open de France. In fact, many of his countrymen are -- six Frenchmen finished inside the 2005 Order of Merit's top 70.
'Every week there seems to be a French player challenging or in the top ten, and that is good for everything and everyone,' said Delamontagne. 'Even in practice now on Tuesdays we have a lot of fun with all the other guys and we try to make a few birdies to beat each other.'
Three of Delamontagne's countrymen -- Jean van de Velde, Thomas Levet and Gregory Bourdy -- are tied for 63rd place at 1-over-par 73. There are six Frenchman overall in the 144-player field.
'We have players with a lot of experience...so for a young player like me it is good to stick with these players and learn from them,' said Delamontagne.
Plaphol, a two-time winner on the Asian Tour, collected his eagles at the 552- yard fourth, where he knocked a three wood within 3 feet, and the 516-yard eighth, where he landed close with a 4 iron.
The 31-year old played in seven European Tour events during the 2005 season, finishing tied for third place at this event as well as at the TCL Classic.
'I've been playing all right coming into the week and hopefully I can keep it going,' said Plaphol.
Tied for fifth place at 4-under-par 68 were Andrew Butterfield, Terry Pilkadaris, Johan Skold, Miles Tunnicliff, Oliver Wilson and Simon Yates. Eleven players were knotted one stroke further back in 11th place.